Onetime Trump campaign chairman Paul Manafort keeps three U.S. passports with different identification numbers and submitted 10 passport applications in as many years, the office of Special Counsel Robert Mueller disclosed in a new court filing Tuesday arguing that Manafort poses a significant flight risk.

The 17-page filing came one day after Manafort and longtime business partner Rick Gates pleaded not guilty to an unsealed 12-count indictment alleging conspiracy to launder money, making false statements and other charges in connection with their work advising a Russia-friendly political party in Ukraine.

In the first criminal allegations to come from probes into possible Russian influence in U.S. political affairs, prosecutors pressed their case against the two defendants, who face a hearing Thursday to set bail terms. A U.S. magistrate on Monday put the men on home confinement pending that hearing after Manafort, 68, pledged to pay a $10 million penalty and Gates a $5 million one if they failed to appear.

Prosecutors argued in the new filing that they "pose a risk of flight" based on a "history of deceptive and misleading conduct," the evidence against them, and their wealth and foreign connections.

The incentive to flee is even stronger "for a defendant such as Manafort, who is in his late 60s," the government observed, noting that he faces a recommended sentence of about 12 to 15 years in prison if convicted, and Gates 10 to 12 years, not counting "related frauds."

"Manafort's financial holdings are substantial, if difficult to quantify precisely because of his varying representations. . . . The full extent of [his assets] is unclear," they said. Manafort, for instance, reported $42 million in assets in March 2016; $136 million that May; and $28 million and $63 million that August, in two separate financial applications, the government said.

Gates listed his and his wife's net worth as $30 million in a February 2016 application for a line of credit, but just $2.6 million in a March 2016 residential loan application.

Manafort attorney Kevin Downing did not immediately respond to a request for comment Tuesday evening, but told the court Monday that his client "definitely disagree[d]" with prosecutors using the " valuation of assets that fluctuate greatly in different countries" to argue against his release.

Separately, outside the courthouse, Downing said, "There is no evidence that Mr. Manafort and the Trump campaign colluded with the Russian government." Downing called "ridiculous" the charges, which he characterized as interpreting Manafort's maintaining of offshore accounts as a means to bring his funds into the United States as a scheme to conceal assets.

The new court filing was disclosed after business hours after prosecutors asked - and the court ordered - that portions of the case be unsealed Tuesday.

U.S. Magistrate Deborah Robinson had granted prosecutors' motion Friday to seal the entire case including the indictment and any warrants, and any other related matters, citing concern that disclosure could cause Manafort or Gates to flee or "to destroy (or tamper with) evidence."